Anode for Lithium Secondary Battery, Lithium Secondary Battery Including the Same and Method of Fabricating the Same

Abstract

An anode for a lithium secondary battery according to an embodiment of the present invention includes a current collector, and an anode active material layer coated on the current collector. The anode active material layer includes an anode active material that includes natural graphite particles, and has an electrode density of 1.50 g/cc or more. An XRD orientation index defined as I(004)/I(110) is 8 or less, I(004) is a peak intensity corresponding to a (004) plane of the anode active material obtained by an XRD measurement from the anode active material layer, and I(110) is a peak intensity corresponding to a (110) plane of the anode active material obtained by the XRD measurement from the anode active material layer.

What is claimed is: 
     
         1 . An anode for a lithium secondary battery, comprising
 a current collector; and   an anode active material layer coated on the current collector, the anode active material layer comprising an anode active material that comprises natural graphite particles and having an electrode density of 1.50 g/cc or more,   wherein an XRD orientation index defined as I(004)/I(110) is 8 or less,   I(004) is a peak intensity corresponding to a (004) plane of the anode active material obtained by an XRD measurement from the anode active material layer, and   I(110) is a peak intensity corresponding to a (110) plane of the anode active material obtained by the XRD measurement from the anode active material layer.   
     
     
         2 . The anode for a lithium secondary battery of  claim 1 , wherein the XRD orientation index is in a range from 2 to 8. 
     
     
         3 . The anode for a lithium secondary battery of  claim 1 , wherein the electrode density of the anode active material layer is in a range from 1.50 g/cc to 1.80 g/cc. 
     
     
         4 . The anode for a lithium secondary battery of  claim 1 , wherein the electrode density of the anode active material layer is in a range from 1.70 g/cc to 1.80 g/cc. 
     
     
         5 . The anode for a lithium secondary battery of  claim 1 , wherein a sphericity of the natural graphite particles is in a range from 0.88 to 0.99. 
     
     
         6 . The anode for a lithium secondary battery of  claim 1 , wherein the anode active material further comprises an amorphous carbon layer formed on the natural graphite particles. 
     
     
         7 . The anode for a lithium secondary battery of  claim 6 , wherein a weight ratio of the amorphous carbon layer relative to a weight of the natural graphite particles is in a range from 1 wt % to 10 wt %. 
     
     
         8 . The anode for a lithium secondary battery of  claim 1 , wherein a porosity of the natural graphite particles measured by a nitrogen adsorption method is in a range from 0.01 g/cm 3  to 0.03 g/cm 3 . 
     
     
         9 . A lithium secondary battery, comprising
 a cathode comprising lithium-transition metal composite oxide particles as a cathode active material; and   the anode for a lithium secondary battery of  claim 1  facing the cathode.   
     
     
         10 . A method of fabricating an anode for a lithium secondary battery, comprising the steps of:
 preparing an anode slurry that comprises an anode active material comprising natural graphite particles;   forming a preliminary anode active material layer by coating and drying the anode slurry on a current collector; and   pressing the preliminary anode active material layer to form an anode active material layer having an electrode density of 1.50 g/cc or more;   wherein a difference between the XRD orientation indexes of the anode active material layer and the preliminary anode active material layer is 6 or less, and   wherein the XRD orientation index is defined as I(004)/I(110), I(004) is a peak intensity corresponding to a (004) plane of the anode active material obtained by an XRD measurement, and I(110) is a peak intensity corresponding to a (110) plane of the anode active material obtained by the XRD measurement.   
     
     
         11 . The method of  claim 10 , wherein the XRD orientation index of the anode active material layer is 8 or less. 
     
     
         12 . The method of  claim 10 , wherein the XRD orientation index of the preliminary anode active material layer is 2 or more. 
     
     
         13 . The method of  claim 10 , wherein the electrode density of the anode active material layer is in a range from 1.50 g/cc to 1.80 g/cc. 
     
     
         14 . The method of  claim 10 , wherein the electrode density of the anode active material layer is in a range from 1.70 g/cc to 1.80 g/cc. 
     
     
         15 . The method of  claim 10 , wherein a sphericity of the natural graphite particles is in a range from 0.88 to 0.99. 
     
     
         16 . The method of  claim 10 , wherein the preparing the anode slurry comprises forming an amorphous carbon layer on surfaces of the natural graphite particles.